9a^2-18a-62=0

Solution for 9a^2-18a-62=0 equation:

9a^2-18a-62=0

a = 9; b = -18; c = -62;
Δ = b2-4ac
Δ = -182-4·9·(-62)
Δ = 2556
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2556}=\sqrt{36*71}=\sqrt{36}*\sqrt{71}=6\sqrt{71}$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-18)-6\sqrt{71}}{2*9}=\frac{18-6\sqrt{71}}{18}
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-18)+6\sqrt{71}}{2*9}=\frac{18+6\sqrt{71}}{18}
$